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Centro de Astrofísica da Universidade do Porto

Varying couplings in the early universe: correlated variations of α and G

C. J. A. P. Martins, E. Menegoni, S. Galli, G. Mangano, A. Melchiorri

The Cosmic Microwave Backround anisotropies provide an unique opportunity to constrain simultaneous variations of the fine-structure constant α and Newton’s gravitational constant G. Those correlated variations are possible in a wide class of theoretical models In this brief paper we show that the current data, assuming that particle masses are constant, gives no clear indication for such variations, but already prefers that any relative variations in α should be of the same sign of those of G for variations of ∼ 1%. We also show that a cosmic complementarity is present with big bang nucleosynthesis and that a combination of current CMB and big bang nucleosynthesis data strongly constraints simultaneous variations in α and G. We finally discuss the future bounds achievable by the Planck satellite mission.

Physical Review D
Volume 82, Page 023532_1
July 2010

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Institute of Astrophysics and Space Sciences (IA) is a new but long anticipated research infrastructure with a national dimension. It embodies a bold but feasible vision for the development of Astronomy, Astrophysics and Space Sciences in Portugal, taking full advantage and fully realizing the potential created by the national membership of the European Space Agency (ESA) and the European Southern Observatory (ESO). IA resulted from the merging the two most prominent research units in the field in Portugal: the Centre for Astrophysics of the University of Porto (CAUP) and the Center for Astronomy and Astrophysics of the University of Lisbon (CAAUL). It currently hosts more than two-thirds of all active researchers working in Space Sciences in Portugal, and is responsible for an even greater fraction of the national productivity in international ISI journals in the area of Space Sciences. This is the scientific area with the highest relative impact factor (1.65 times above the international average) and the field with the highest average number of citations per article for Portugal.

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